We have disrupted expression of the mitochondrial Friedreich ataxia protein frataxin specifically in murine hepatocytes to generate mice with impaired mitochondrial function and decreased oxidative phosphorylation. These animals have a reduced life span and develop multiple hepatic tumors. Livers also show increased oxidative stress, impaired respiration and reduced ATP levels paralleled by red...

The respiration, membrane potential (Deltapsi), and oxidative phosphorylation of mitochondria in situ were determined in spheroplasts obtained from Candida albicans control strain ATCC 90028 by lyticase treatment. Mitochondria in situ were able to phosphorylate externally added ADP (200 microM) in the presence of 0.05% BSA. Mitochondria in situ generated and sustained stable mitochondrial Delta...

in effluent-treatment processes, the major concern is with biomass production, whereas in many microbial processes it is important to produce an extracellular product, e.g. amino acid, organic acid or polysaccharide. For microbial-product formation there must often be a diversion of energy, reductant and carbon away from biomass production into product formation, and a possible energy-dependent...

Respiration, oxidative phosphorylation, calcium uptake, and the mitochondrial membrane potential of trophozoites of the malaria parasite Plasmodium berghei were assayed in situ after permeabilization with digitonin. ADP promoted an oligomycin-sensitive transition from resting to phosphorylating respiration. Respiration was sensitive to antimycin A and cyanide. The capacity of trophozoites to su...

Respiration, oxidative phosphorylation, calcium uptake, and the mitochondrial membrane potential of trophozoites of the malaria parasite Plasmodium berghei were assayed in situ after permeabilization with digitonin. ADP promoted an oligomycin-sensitive transition from resting to phosphorylating respiration. Respiration was sensitive to antimycin A and cyanide. The capacity of trophozoites to su...

There have been many conflicting reports on the effects of x-rays in vitro and in vivo on respiration and phosphorylation in various animal tissues. Kusnets (1) reported a decrease in spleen respiration within 30 minutes after rats had received whole body irradiation of 800 r, and Sullivan and Dubois (2) recorded a similar decrease with 400 r which reached a maximum after 48 hours. Barron (3) f...

The mechanism of the process of oxidative phosphorylation in the respiratory chain is still quite obscure. One approach to its study has involved an investigation of inhibitors of this phenomenon (l-3). Thus, by use of various inhibitory compounds of known chemical composition some knowledge may be gleaned of the sequence of reactions comprising the over-all process, and of the nature of variou...

In psoriasis, keratinocytes of the healthy-looking uninvolved skin are more sensitive to stress. Our previous study suggested that cell-stress proteins showing altered expression in psoriatic vs. healthy can affect mitochondrial functions. Therefore, we aimed examine whether involved these alterations, and compared functions between cultured detail by high–resolution respirometry. We did not fi...

The most immediate effect of anaerobic soil conditions on plants is a reduction in aerobic respiration in roots. Root cells switch to anaerobic respiration which is much less efficient than aerobic respiration. Under normal aerobic conditions 30 to 32 mol ATP are produced per hexose sugar by oxidative phosphorylation, citric acid cycle and glucolysis, whereas at anoxic conditions only 2 mol ATP...

Crane and Lipmann (1) have shown that arsenate uncouples oxidative phosphorylation in intact rat liver mitochondria, and that this effect can be reversed by phosphate. They postulated that arsenate competes with phosphate at the site of phosphate uptake. It has also been observed that arsenate can stimulate the respiration of intact mitochondria (1) and of submitochondrial particles’ in the abs...